摘要
作者研究了负载型的Cu-O,Mn-O,Cu-Mn-O加入氧化铈后的氧性质和固相结构,表明铈可加速催化剂中体相氧的迁移,提高表面氧的稳定性,改善催化剂的贮氧性能和氧化-还原可复性能,抑制活性相的聚集以提高其分散度.铈的存在还能改善铜基负载型催化剂的性能,提高2NO+CO→N_2O+CO_2反应的速度.本文以甲苯的催化燃烧作为研究对象,考察了甲苯在Cu-Mn-Ce-O催化剂上的催化氧化性能和氧化铈对其催化行为的影响.
The micro-reactor, temperature-programmed desorption and pulse injection of toluene-air were used to study the adsorption and catalytic combustion of toluene over Cu-Mn-Ce-O (I) supported on alumina. The results show that the catalytic activity of Cu-Mn-O supported on alumina is better than (I) for toluene deep oxidation in rich oxygen circumstance (PO2 = 21.2KPa), and in lean oxygen circumstance (PO2= 5.07KPa) the situation turns out contrary to rich oxygen circumstance. In the case of Mn-Ce-O supported on alumina, there is a cooperation for adsorbing toluene between Ce and Mn. Cu in (I) is the active site for adsorbing toluene, the addition of Mn and/or Ce to CuO can enhance its capacity for adsorbing toluene and the order is Mn>Mn-Ce>Ce. The results from toluene-air titration and catalytic oxidation of toluene in different oxygen pressures indicate that the lattice oxygen in (I) is the main factor making toluene oxidized completely, gaseous oxygen can oxidize toluene adsorbed on surface of (I) to CO only.
